Concrete use in the construction industry is widespread, and it paves the way for creating massive structures like buildings, highways, bridges, etc. In addition to its popularity, it tends to get cracks, and there is always a chance of structure breakdown.
As strong concrete is in compression, it is weak in tensile strength. That’s why you can’t use it separately in any infrastructure. So, first of all, an engineer increases the tensile strength of concrete by incorporating rebar (reinforced steel) in concrete. In this way, you can drastically boost concrete tensile strength that way.
Related:
Contents
Rebar: An Overview
Rebar is basically reinforced steel that is specially designed to enhance structural strength and tension. Moreover, rebar contains only steel in its composition. That’s why it adds strength and load-bearing ability to structures. Besides, the heat expansion coefficient of the rebar and concrete is almost identical, which reduces the chance of structure cracking considerably.
How does rebar bestows strength to the structure?
The most important question regarding rebar is how its integration with concrete adds strength and reduces tension over the structure. In general, the liquid concrete is spewed over the rebar, frames, and cages. After the concrete is spewed in the rebar cage, the stones and gravel get latched into the cage as well.
The concrete inside the cage has better tensile strength than the original concrete. Moreover, an original concrete has ultimate strength against the forces that press but not against the forces that bend. Besides, the improved tensile strength of the concrete by integration with rebar makes this duo ideal for use in any construction project.
Can we weld reinforcing bars?
Generally, reinforcing bars are available in various grades and sizes, and all of them are not weldable. That’s why you must have a knowledge of which rebars you can weld and which you can not. So, to know which grades are weldable or not, then keep on going.
What are weldable rebars?
Those reinforcement bars that have low alloy steel are weldable. Moreover, the ratio of carbon to steel is less than other rebar grades, which makes it ideal for coupling with concrete. This type of rebar is not only weldable but also creates a strong bond with the concrete to bear the significant load, thus reducing tension. Besides, this is the only type of reinforcement bar for which you don’t need to consider any specific thing.
What are non-weldable rebars?
The composition of the steel is the thing that indicates whether it is weldable or not. Besides, if a steel composition infers high carbon content, then it means that the rebar isn’t weldable. The reason is that steel with more carbon percentage is brittle, which is not good to create solid and stable bonds with concrete. Moreover, they aren’t flexible but have incredible strength. Therefore, deformation occurs when an ultimate load is placed over these rebar grades.
Reinforcement bar welding
Rebar welding is very crustal in structural engineering as it is the only way to create rebar mats or cages. Moreover, these cages are filled with concrete in this way; concrete gets the absolute tensile strength that is necessary to develop crack-free mega structures.
Besides, rebar welding is feasible, and below given are the steps to accomplish it:
Getting the appropriate rebar
There are many kinds of rebars used in the construction industry. These are:
- Deformed Steel Bars
- Mild Steel Bars
- European Steel Bars
- Galvanized Steel Bars
- Glass Fiber Reinforced Polymer Bars
- Stainless Steel Rebars
- High Strength Rebars
- Epoxy Coated Rebars
- Thermo Mechanically Treated Bars
Each of the rebars mentioned above is different in its properties. Stainless steel reinforcement bar has the premium quality among all, as it contains a minimal percentage of carbon, but it is costly. So, we suggest you pick the rebar according to the project you will perform.
Preheating
You don’t always need to preheat rebar before welding because it depends upon the carbon content of the regard, which indicates whether you need a preheating session for rebars or not. Let’s say you have high-carbon steel; then you have to preheat it at the ultimate level or vice versa.
So, it is necessary to estimate the carbon content in the reinforcement bars you have, which is tricky because manufacturers mainly don’t give that information. We suggest you request the manufacturer to tell you the exact figures for the carbon percentage in rebars. You will save a lot of money on preheating if you know.
Choosing the adequate filler
There are only three welding techniques that you can use to weld rebars: shielded metal arc welding (SMAW), metal inert gas (MIG) welding, and flux core arc welding (FCAW). Moreover, this procedure will determine which type of filler you need to execute your endeavor. So, it is clear that the filler metal should be according to the type of welding you are employing. Otherwise, you’ll not get the results you desire.
Execution of welds
You can’t form all types of welds when welding rebars as specific welds are allowable for this undertaking. The type of welds you can create on rebars is butt joints, lap joints, and splices. Another thing that Structural Welding Code suggests is that when welding, rebars must be parallel or perpendicular for better productivity and quality.
